The present invention relates to a semiconductor memory device and, more particularly, to a semiconductor memory device having a memory cell for magnetically storing a data signal.
In recent years, attention is paid to an MRAM (Magnetic Random Access Memory) as a semiconductor memory device capable of storing data in a nonvolatile manner with low power consumption. An MRAM includes a plurality of memory cells MC arranged in a plurality of rows and a plurality of columns, a plurality of digit lines DL provided in correspondence with the plural rows, and a plurality of bit lines BL provided in correspondence with the plural columns. In writing operation, magnetization current Im is made to flow to a selected digit line DL to activate the memory cells MC corresponding to the digit line, and write current Iw in the direction according to the logic of a data signal is made to flow to the selected bit line BL, thereby writing the data signal to the memory cell MC arranged at the cross point of the digital line DL and the bit line BL selected (refer to, for example, Japanese Unexamined Patent Publication No. 2004-185752).